Spring Cloud Gateway 服务网关的部署与使用详细讲解

	<properties>
		<spring-boot.version>2.3.2.RELEASE</spring-boot.version>
		<spring-cloud.version>Hoxton.SR9</spring-cloud.version>
		<spring-cloud-alibaba.version>2.2.6.RELEASE</spring-cloud-alibaba.version>
	</properties>
 
	<!-- 只声明依赖，不引入依赖 -->
	<dependencyManagement>
		<dependencies>
			<!-- 声明SpringBoot版本 -->
			<dependency>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-dependencies</artifactId>
				<version>${spring-boot.version}</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
			<!-- 声明springCloud版本 -->
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-dependencies</artifactId>
				<version>${spring-cloud.version}</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
			<!-- 声明 springCloud Alibaba 版本 -->
			<dependency>
				<groupId>com.alibaba.cloud</groupId>
				<artifactId>spring-cloud-alibaba-dependencies</artifactId>
				<version>${spring-cloud-alibaba.version}</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
	</dependencyManagement>

<!-- 引入gateway网关 -->
<dependency>
	<groupId>org.springframework.cloud</groupId>
	<artifactId>spring-cloud-starter-gateway</artifactId>
	<exclusions>
        <exclusion>
			<groupId>org.springframework.boot</groupId>
        	<artifactId>spring-boot-starter-web</artifactId>
        </exclusion>
    </exclusions>
</dependency>

server:
  port: 9023
  servlet:
    context-path: /${spring.application.name}
spring:
  application:
    name: gateway

spring:
  cloud:
    gateway:
      # 路由数组：指当请求满足什么样的断言时，转发到哪个服务上
      routes:
        # 路由标识，要求唯一，名称任意
        - id: gateway-provider_1
		  # 请求最终被转发到的目标地址
          uri: http://localhost:9024
          # 设置断言
          predicates:
            # Path Route Predicate Factory 断言，满足 /gateway/provider
@Component
@Slf4j
public class AuthorizeGatewayFilterFactory extends AbstractGatewayFilterFactory<AuthorizeGatewayFilterFactory.Config> {
 
    private static final String AUTHORIZE_TOKEN = "token";
 
    //构造函数，加载Config
    public AuthorizeGatewayFilterFactory() {
        //固定写法
        super(AuthorizeGatewayFilterFactory.Config.class);
        log.info("Loaded GatewayFilterFactory [Authorize]");
    }
 
    //读取配置文件中的参数 赋值到 配置类中
    @Override
    public List<String> shortcutFieldOrder() {
        //Config.enabled
        return Arrays.asList("enabled");
    }
 
    @Override
    public GatewayFilter apply(AuthorizeGatewayFilterFactory.Config config) {
        return (exchange, chain) -> {
            //判断是否开启授权验证
            if (!config.isEnabled()) {
                return chain.filter(exchange);
            }
 
            ServerHttpRequest request = exchange.getRequest();
            HttpHeaders headers = request.getHeaders();
            //从请求头中获取token
            String token = headers.getFirst(AUTHORIZE_TOKEN);
            if (token == null) {
                //从请求头参数中获取token
                token = request.getQueryParams().getFirst(AUTHORIZE_TOKEN);
            }
 
            ServerHttpResponse response = exchange.getResponse();
            //如果token为空，直接返回401，未授权
            if (StringUtils.isEmpty(token)) {
                response.setStatusCode(HttpStatus.UNAUTHORIZED);
                //处理完成，直接拦截，不再进行下去
                return response.setComplete();
            }
            
            //授权正常，继续下一个过滤器链的调用
            return chain.filter(exchange);
        };
    }
 
    @Data
    @AllArgsConstructor
    @NoArgsConstructor
    public static class Config {
        // 控制是否开启认证
        private boolean enabled;
    }
}

spring:
  cloud:
    gateway:
      routes:
        - id: gateway-provider_1
          uri: http://localhost:9024
          predicates:
            - Path=/gateway/provider
    @Bean
    @Order (-1)
    public WebFilter apiPrefixFilter()
    {
        return (exchange, chain) ->
        {
            ServerHttpRequest request = exchange.getRequest();
            String path = request.getURI().getRawPath();
 
            path = path.startsWith(prefix) ? path.replaceFirst(prefix, "") : path;
            ServerHttpRequest newRequest = request.mutate().path(path).build();
 
            return chain.filter(exchange.mutate().request(newRequest).build());
        };
    }
}

<!-- Apollo 统一配置中心 -->
<dependency>
    <groupId>com.ctrip.framework.apollo</groupId>
    <artifactId>apollo-client</artifactId>
    <version>1.7.0</version>
</dependency>

import com.ctrip.framework.apollo.enums.PropertyChangeType;
import com.ctrip.framework.apollo.model.ConfigChange;
import com.ctrip.framework.apollo.model.ConfigChangeEvent;
import com.ctrip.framework.apollo.spring.annotation.ApolloConfigChangeListener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.context.environment.EnvironmentChangeEvent;
import org.springframework.cloud.gateway.config.GatewayProperties;
import org.springframework.cloud.gateway.event.RefreshRoutesEvent;
import org.springframework.cloud.gateway.route.RouteDefinitionWriter;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationEventPublisherAware;
import org.springframework.context.annotation.Configuration;
 
import java.util.ArrayList;
 

@Configuration
public class GatewayPropertRefresher implements ApplicationContextAware, ApplicationEventPublisherAware
{
    private static final Logger logger = LoggerFactory.getLogger(GatewayPropertRefresher.class);
 
    private static final String ID_PATTERN = "spring\\.cloud\\.gateway\\.routes\\[\\d+\\]\\.id";
 
    private static final String DEFAULT_FILTER_PATTERN = "spring\\.cloud\\.gateway\\.default-filters\\[\\d+\\]\\.name";
 
 
    private ApplicationContext applicationContext;
 
    private ApplicationEventPublisher publisher;
 
    @Autowired
    private  GatewayProperties gatewayProperties;
 
    @Autowired
    private RouteDefinitionWriter routeDefinitionWriter;
 
 
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }
 
    @Override
    public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
        this.publisher = applicationEventPublisher;
    }
 
 
    
    @ApolloConfigChangeListener(interestedKeyPrefixes = "spring.cloud.gateway.")
    public void onChange(ConfigChangeEvent changeEvent)
    {
        refreshGatewayProperties(changeEvent);
    }
 
    
    private void refreshGatewayProperties(ConfigChangeEvent changeEvent)
    {
        logger.info("gateway网关配置 刷新开始！");
 
        preDestroyGatewayProperties(changeEvent);
        //更新配置
        this.applicationContext.publishEvent(new EnvironmentChangeEvent(changeEvent.changedKeys()));
        //更新路由
        refreshGatewayRouteDefinition();
 
        logger.info("gateway网关配置 刷新完成！");
    }
 
    
    private synchronized void preDestroyGatewayProperties(ConfigChangeEvent changeEvent)
    {
        logger.info("Pre Destroy GatewayProperties 操作开始!");
 
        final boolean needClearRoutes = this.checkNeedClear(changeEvent, ID_PATTERN, this.gatewayProperties.getRoutes().size());
        if (needClearRoutes)
        {
            this.gatewayProperties.setRoutes(new ArrayList());
        }
 
        final boolean needClearDefaultFilters = this.checkNeedClear(changeEvent, DEFAULT_FILTER_PATTERN, this.gatewayProperties.getDefaultFilters().size());
        if (needClearDefaultFilters)
        {
            this.gatewayProperties.setRoutes(new ArrayList());
        }
 
        logger.info("Pre Destroy GatewayProperties 操作完成!");
    }
 
 
    private void refreshGatewayRouteDefinition()
    {
        logger.info("Refreshing Gateway RouteDefinition 操作开始!");
 
        this.publisher.publishEvent(new RefreshRoutesEvent(this));
 
        logger.info("Gateway RouteDefinition refreshed 操作完成!");
    }
 
    
    private boolean checkNeedClear(ConfigChangeEvent changeEvent, String pattern, int existSize) {
 
        return changeEvent.changedKeys().stream().filter(key -> key.matches(pattern)).filter(key ->
        {
            ConfigChange change = changeEvent.getChange(key);
            return PropertyChangeType.DELETED.equals(change.getChangeType());
        }).count() == existSize;
    }
}

@Slf4j
@Order(-1)
@Component
@RequiredArgsConstructor
public class GlobalErrorExceptionHandler implements ErrorWebExceptionHandler {
 
 private final ObjectMapper objectMapper;
 
 @SuppressWarnings({"rawtypes", "unchecked", "NullableProblems"})
 @Override
 public Mono<Void> handle(ServerWebExchange exchange, Throwable ex) {
  ServerHttpResponse response = exchange.getResponse();
  if (response.isCommitted()) {
   return Mono.error(ex);
  }
 
  // JOSN格式返回
  response.getHeaders().setContentType(MediaType.APPLICATION_JSON);
  if (ex instanceof ResponseStatusException) {
   response.setStatusCode(((ResponseStatusException) ex).getStatus());
  }
 
  return response.writeWith(Mono.fromSupplier(() -> {
   DataBufferFactory bufferFactory = response.bufferFactory();
   try {
    //todo 返回响应结果，根据业务需求，自己定制
    CommonResponse resultMsg = new CommonResponse("500",ex.getMessage(),null);
    return bufferFactory.wrap(objectMapper.writeValueAsBytes(resultMsg));
   }
   catch (jsonProcessingException e) {
    log.error("Error writing response", ex);
    return bufferFactory.wrap(new byte[0]);
   }
  }));
 }
}